Blood Test Guide

Estimated average blood sugar over 2-3 months from HbA1c.

Your blood sugar level after not eating for at least 8 hours. This is the primary screening test for diabetes — one of India's biggest health challenges.

Fructosamine measures glycated (sugar-coated) proteins in your blood, reflecting average blood sugar over the past 2-3 weeks. It's a shorter-term average than HbA1c (which covers 2-3 months).

GAD antibodies are autoimmune markers that attack insulin-producing beta cells in the pancreas. Their presence indicates that the immune system is destroying the pancreas's ability to make insulin — the hallmark of type 1 and autoimmune diabetes.

Like HbA1c but reflects average blood sugar over 2-3 weeks instead of 2-3 months. Useful when HbA1c is unreliable — which is relevant in India where thalassemia and hemoglobin variants are common.

HbA1c shows your average blood sugar over the past 2-3 months. Unlike fasting sugar (which is a snapshot), this gives the big picture. It's the gold standard for diabetes monitoring.

Measures how resistant your body is to insulin.

Your blood sugar level 2 hours after eating a meal. Shows how well your body handles sugar after food — an important complement to fasting sugar.

Blood sugar measured at any time, regardless of when you last ate. Used as a quick check, not a formal diagnostic test.

Protein component of LDL and VLDL. Better predictor of cardiovascular risk than LDL. Main protein in atherogenic particles. One ApoB per LDL particle.

HDL is the 'good' cholesterol — it carries cholesterol away from your arteries and back to the liver for disposal. Higher is better. Think of it as the cleanup crew.

LDL is the 'bad' cholesterol — it deposits cholesterol in your artery walls, forming plaques that can lead to heart attacks and strokes. Lower is generally better.

The ratio of bad cholesterol to good cholesterol. A direct measure of how balanced your cholesterol profile is.

Genetic variant of LDL associated with increased cardiovascular risk. Similar to LDL but more atherogenic. Promotes clotting and inflammation.

All cholesterol that is NOT HDL — includes LDL, VLDL, and other harmful particles.

The total amount of cholesterol in your blood — a waxy substance your body needs to build cells, but too much increases heart disease risk. This number combines your 'good' and 'bad' cholesterol.

The ratio of your total cholesterol to your good cholesterol. A lower ratio means a better balance. Many doctors consider this more useful than total cholesterol alone.

Triglycerides are fats in your blood that your body uses for energy. After you eat, your body converts excess calories into triglycerides and stores them in fat cells.

VLDL carries triglycerides through your blood. Like LDL, it contributes to plaque buildup in arteries. It's usually calculated from your triglyceride level.

The most abundant protein in your blood, made by the liver. Albumin keeps fluid in your blood vessels and carries hormones, vitamins, and medications through your bloodstream.

The ratio of albumin to globulin in your blood. A quick way to check the balance between the two main protein types. Low ratio is more clinically significant than high.

An enzyme found in the liver, bones, kidneys, and intestines. Important for distinguishing between liver problems and bone problems when other markers are abnormal.

Ammonia is a toxic waste product from protein metabolism that your liver normally converts to urea for safe excretion by the kidneys. When the liver is severely damaged, ammonia builds up in the blood and can affect brain function.

Ceruloplasmin is a copper-carrying protein made by the liver. It carries about 95% of the copper in your blood and also helps with iron metabolism. It's the key test for diagnosing Wilson's disease.

The portion of bilirubin that has been processed by the liver. Helps distinguish whether a bilirubin problem is coming from the liver itself or from before it reaches the liver.

An enzyme mainly found in the liver and bile ducts. It's the most sensitive marker for bile duct problems and alcohol-related liver damage.

A group of proteins in your blood that includes antibodies (immunoglobulins). Your immune system makes most globulins. Higher levels often mean your immune system is active.

The portion of bilirubin that hasn't been processed by the liver yet. High levels suggest the problem is happening before the liver — usually too many red blood cells being destroyed.

LDH is an enzyme found in almost all body tissues — heart, liver, kidneys, muscles, and blood cells. It's released when cells are damaged, making it a general marker of tissue injury rather than specific to one organ.

An enzyme found in your liver, heart, and muscles. When these organs are damaged, SGOT leaks into your blood. Indian labs commonly use 'SGOT' while Western labs say 'AST' — same test.

An enzyme found primarily in the liver. SGPT is more specific to the liver than SGOT — when it's high, the liver is almost certainly involved. This is the single best screening marker for liver health.

Bilirubin is a yellow pigment produced when your liver breaks down old red blood cells. It's what makes jaundice yellow. Your liver processes it and sends it out through bile.

The total amount of protein in your blood, mainly albumin and globulin. Your liver makes most blood proteins, so this reflects both liver function and nutritional status.

This test measures the total amount of protein your kidneys leak into urine over a full 24-hour collection period. It's the gold standard for quantifying protein loss and assessing kidney damage severity.

ACR measures albumin relative to creatinine in a urine sample. It standardizes the microalbumin result so that urine concentration doesn't affect the reading. It's the preferred screening test for kidney damage in diabetes and hypertension.

Urea is a waste product from protein breakdown, filtered out by your kidneys. When kidneys aren't working well, urea builds up in your blood.

The ratio of blood urea to creatinine. Helps distinguish between different causes of kidney problems — specifically whether the issue is before the kidney (dehydration, bleeding) or in the kidney itself.

Calcium is essential for bones, muscles, nerves, and heart function. Your blood calcium level is tightly regulated by parathyroid hormone and vitamin D.

Chloride works with sodium to maintain fluid balance and acid-base balance in your body. It usually moves in tandem with sodium.

Cystatin C is a protein produced by all cells at a constant rate and filtered by the kidneys. It's an alternative and often more accurate marker of kidney function compared to creatinine, as it's not affected by muscle mass, diet, or sex.

The estimated rate at which your kidneys filter blood — the single best measure of kidney function. Calculated from creatinine, age, sex, and sometimes body size. Higher is better.

Microalbumin measures tiny amounts of albumin protein leaking into your urine. Healthy kidneys keep albumin in the blood — even small leaks indicate early kidney damage, especially from diabetes or high blood pressure.

Phosphorus works with calcium to build bones and teeth. Your kidneys regulate phosphorus levels. It's often tested alongside calcium and kidney function markers.

Potassium is critical for heart rhythm, muscle function, and nerve signals. Your body keeps potassium in a very tight range because abnormal levels directly affect your heart.

Creatinine is a waste product from normal muscle activity, filtered by your kidneys at a very steady rate. This makes it one of the most reliable markers for kidney function.

Sodium is the main electrolyte that controls water balance in your body. Your kidneys tightly regulate sodium levels. It's essential for nerve and muscle function.

Uric acid is a waste product from the breakdown of purines (found in certain foods and your own cells). Your kidneys filter it out. High levels can form crystals in your joints.

Early indicator of kidney damage by measuring albumin leaking into urine.

Antibodies against thyroid peroxidase. Autoimmune thyroid indicator.

T3 is the more active thyroid hormone — your body converts T4 to T3. Free T3 is most useful for diagnosing hyperthyroidism, where it may rise before T4 does.

The active, unbound form of the main thyroid hormone (T4). Free T4 is what actually reaches your cells and affects your metabolism. Tested alongside TSH to confirm and characterize thyroid problems.

Antibodies against thyroid enzyme. Indicates autoimmune thyroid disease. Marker of autoimmune attack on thyroid gland.

Total T3 measures both bound and free T3 in your blood. Less precise than Free T3 because it's affected by protein levels, but commonly reported on Indian lab panels.

Total T4 measures both bound and free thyroxine. Like Total T3, it's affected by protein levels but still commonly used on Indian thyroid panels.

TSH is the master controller of your thyroid. Your brain releases TSH to tell the thyroid to make more hormones. Paradoxically, high TSH means LOW thyroid function (the brain is shouting louder because the thyroid isn't listening).

Ferritin is your body's iron storage protein — it reflects how much iron you have in reserve. The single best test for iron deficiency. Low ferritin = your iron stores are depleted.

The amount of iron circulating in your blood right now. Iron is essential for making hemoglobin and carrying oxygen. This is a snapshot — it fluctuates throughout the day and with meals.

TIBC measures how much iron your blood could carry if all the transport protein (transferrin) were fully loaded. Think of it as the total capacity of the iron delivery trucks in your blood.

The percentage of iron-carrying protein (transferrin) that is actually loaded with iron. Combines serum iron and TIBC into one useful number.

Acid-base balance.

Magnesium is involved in over 300 enzymatic reactions — muscle and nerve function, blood sugar control, blood pressure regulation, and bone development. Often called the 'forgotten electrolyte' because deficiency is common but rarely tested.

CRP is a protein your liver produces in response to inflammation. It's a general alarm bell — it shoots up within hours when there's infection, injury, or inflammation anywhere in your body.

Amino acid linked to cardiovascular disease risk. Intermediate in methionine metabolism. Requires B12, folate, B6 to metabolize.

AMH (Anti-Mullerian Hormone) is produced by small follicles in the ovaries and is the best single blood test to estimate a woman's remaining egg supply (ovarian reserve). Unlike other hormones, AMH stays relatively stable throughout the menstrual cycle.

Cortisol is your body's main stress hormone, produced by the adrenal glands. It follows a daily rhythm — highest in the early morning (to wake you up) and lowest at midnight. It regulates blood sugar, blood pressure, inflammation, and your sleep-wake cycle.

Stress hormone produced by adrenal glands. Varies by time of day. Regulates stress response, metabolism, blood sugar, blood pressure, immune function, inflammation.

DHEA-S is produced by the adrenal glands and is a precursor to both testosterone and estrogen. It's the most abundant steroid hormone in the body. Levels peak in your 20s and gradually decline with age.

Adrenal androgen precursor to testosterone and estrogen. Precursor to sex hormones. Declines with age. Indicator of adrenal function.

Primary female sex hormone, important for both sexes. Reproductive function, bone health, cardiovascular health, brain function, mood regulation.

Fasting insulin measures how much insulin your pancreas produces when you haven't eaten. Insulin is the hormone that moves sugar from your blood into your cells. High fasting insulin is an early warning sign of diabetes — often abnormal years before blood sugar rises.

Pituitary hormone that regulates reproductive function. Women: Stimulates follicle development. Men: Stimulates sperm production.

Active form of testosterone not bound to proteins. Biologically active testosterone available to tissues.

Follicle Stimulating Hormone (FSH) is made by the pituitary gland and is essential for reproductive function. In women, it stimulates eggs to grow in the ovaries. In men, it supports sperm production. It works alongside LH.

Growth Hormone (GH) is produced by the pituitary gland and is essential for growth in children and maintaining muscle, bone, and metabolism in adults. It's released in pulses, mainly during deep sleep.

Luteinizing Hormone (LH) is produced by the pituitary gland and plays a crucial role in reproduction. In women, an LH surge triggers ovulation. In men, LH stimulates testosterone production. It works in partnership with FSH.

Pituitary hormone that triggers ovulation in women and testosterone production in men. Women: Triggers ovulation. Men: Stimulates testosterone production in testes.

Progesterone is the hormone that prepares your uterus for pregnancy and maintains early pregnancy. It rises in the second half of the menstrual cycle (luteal phase). In men, it's present in very small amounts and is a precursor to other hormones.

Pituitary hormone that stimulates milk production. Stimulates breast milk production. Inhibits reproductive hormones when elevated.

Protein that binds sex hormones, regulating their bioavailability. Binds and transports testosterone and estrogen. Regulates free hormone levels.

Testosterone is the primary male sex hormone, but women need it too in smaller amounts. It plays a key role in muscle mass, bone density, fat distribution, red blood cell production, and sex drive in both genders.

Primary male sex hormone, important for both sexes. Muscle mass, bone density, libido, mood, energy, and sperm production in males. Women need smaller amounts.

D-Dimer is a protein fragment produced when a blood clot dissolves. Elevated levels mean there is increased clot formation and breakdown happening in your body. It is commonly used to rule out dangerous blood clots (DVT and pulmonary embolism).

Fibrinogen is a protein made by your liver that is essential for blood clotting. When you bleed, fibrinogen gets converted into fibrin threads that form the scaffolding of a blood clot.

A standardized version of prothrombin time that works the same regardless of which lab did the test. Essential for patients on blood thinners like warfarin.

Measures how long your blood takes to clot via the extrinsic pathway. Important for monitoring liver function and blood thinner (warfarin) therapy.

Total IgE measures the overall level of immunoglobulin E — the antibody type responsible for allergic reactions and fighting parasites. It's a broad screening test for allergic tendency and parasitic infections.

ANA tests whether your immune system is making antibodies that attack your own cells. A positive ANA does NOT mean you have an autoimmune disease — many healthy people test positive, especially women.

Anti-CCP is a highly specific antibody for rheumatoid arthritis. If positive, there's a strong likelihood of RA. It's more accurate than Rheumatoid Factor for diagnosing RA.

Anti-dsDNA antibodies target your own DNA. They are highly specific for lupus (SLE) and their levels often rise and fall with disease activity, making them useful for both diagnosis and monitoring.

Anti-Thyroglobulin antibodies target thyroglobulin, a protein used by the thyroid to make hormones. Like Anti-TPO, they indicate autoimmune thyroid activity and are often tested alongside Anti-TPO.

Anti-TPO antibodies target an enzyme in your thyroid gland. They're the most common marker for autoimmune thyroid disease (Hashimoto's thyroiditis), which is the leading cause of hypothyroidism in India.

Rheumatoid Factor (RF) is an antibody that can attack healthy tissue. It's associated with rheumatoid arthritis, but a positive RF does NOT mean you have RA — many other conditions and even healthy aging can cause a positive result.

Bone-Specific ALP is the fraction of alkaline phosphatase that comes specifically from bone. Unlike total ALP (which can be from liver or bone), this marker specifically reflects bone-building activity.

CTx (C-Telopeptide) is a fragment released when old bone is broken down. It's the primary marker of bone resorption (destruction). While osteocalcin measures bone building, CTx measures bone breakdown.

Osteocalcin is a protein made by bone-building cells (osteoblasts). It reflects how actively your body is forming new bone — think of it as a marker of bone construction activity.

PTH is a hormone made by the parathyroid glands (four tiny glands behind your thyroid). It controls calcium and phosphorus levels in your blood and is critical for bone health.

Apolipoprotein A1 (ApoA1) is the main protein component of HDL — the "good" cholesterol. It helps remove cholesterol from artery walls and transport it back to the liver for disposal (reverse cholesterol transport). Higher ApoA1 generally means better cardiovascular protection.

CK-MB is an enzyme found predominantly in heart muscle. When the heart is damaged, CK-MB is released into the blood. It was the primary heart attack marker before troponin and is still used alongside it in many Indian labs.

NT-proBNP is a hormone released by your heart when it's under strain or stretched. It's the best blood test for diagnosing and monitoring heart failure. Higher levels mean the heart is working harder than it should.

Troponin I is a protein found exclusively in heart muscle cells. When heart cells are damaged (as in a heart attack), troponin leaks into the blood. It is the gold standard test for diagnosing heart attacks — the most sensitive and specific marker available.

The actual number of eosinophils per unit of blood, rather than a percentage. More accurate than the percentage because it's not affected by changes in other white blood cell types.

Basophils are the rarest type of white blood cell. They play a role in allergic reactions and inflammation.

Eosinophils fight parasites and are involved in allergic reactions. They're particularly relevant in tropical climates.

ESR measures how quickly red blood cells settle to the bottom of a test tube. It's a general indicator of inflammation in your body — not specific to any one condition.

Hemoglobin is the protein in red blood cells that carries oxygen from your lungs to the rest of your body. It's one of the most important markers on any blood test.

Lymphocytes handle viral infections and long-term immunity. They include the T-cells and B-cells you may have heard about.

The average amount of hemoglobin in each red blood cell. Works alongside MCV to classify anemia.

The average concentration of hemoglobin in your red blood cells. Helps distinguish between different types of anemia.

The average size of your red blood cells. This helps your doctor figure out the type of anemia if your hemoglobin is low.

The average size of your platelets. Larger platelets are younger and more active. This gives additional information about platelet function beyond just the count.

Monocytes are white blood cells that clean up dead cells and fight certain infections. They're part of your body's cleanup crew.

Neutrophils are the most common type of white blood cell and your first line of defense against bacterial infections.

The percentage of your blood volume that is made up of red blood cells. It moves in tandem with hemoglobin — if one is abnormal, the other usually is too.

Platelets help your blood clot when you get a cut or injury. Too few and you bleed easily; too many and you risk clots.

Counts the number of red blood cells in your blood. Red blood cells carry oxygen throughout your body.

Measures how much variation there is in the size of your red blood cells. A high number means your red blood cells are very uneven in size.

Reticulocytes are baby red blood cells freshly released from the bone marrow. Their count tells you how actively your bone marrow is producing new red blood cells.

White blood cells are your immune system's soldiers. This count tells you how active your immune system is right now.

Byproduct of insulin production. Indicates how much insulin pancreas makes. Released in equal amounts with insulin. Reflects pancreatic insulin production.

Hormone that regulates blood sugar. Fasting levels indicate insulin resistance. Regulates glucose uptake into cells. Controls blood sugar levels.

Your blood type (A, B, AB, or O) and Rh factor (positive or negative). Important for blood transfusions and pregnancy. Once determined, it never changes.

The Direct Coombs Test (DAT) checks whether antibodies or complement proteins are stuck to the surface of your red blood cells, causing them to be destroyed prematurely (autoimmune hemolytic anemia).

G6PD is an enzyme that protects red blood cells from oxidative damage. G6PD deficiency is one of the most common genetic enzyme deficiencies worldwide, affecting millions of people in India.

Hemoglobin electrophoresis separates and measures the different types of hemoglobin in your blood. It is the key test for diagnosing thalassemia and other hemoglobin disorders, which are very common in India.

A microscopic examination of your blood cells by a pathologist. Unlike automated counts, this gives a visual picture of cell shape, size, and any abnormalities. Often the most informative test on the entire report.

This test detects IgM antibodies against Hepatitis A virus, indicating a current or very recent Hepatitis A infection. Hepatitis A is spread through contaminated food and water and is very common in India.

Blood culture checks whether bacteria or fungi are growing in your bloodstream. Blood is normally sterile — any organism found is a serious matter. This test also identifies which antibiotics will work against the infection (sensitivity testing).

Dengue IgG antibodies indicate a past dengue infection or a secondary (repeat) dengue infection. They appear later than IgM and persist for life.

Dengue IgM antibodies appear after day 5 of infection and indicate a recent or current dengue infection. This test complements the NS1 antigen test.

The NS1 antigen test detects a protein from the dengue virus itself. It is most useful in the first 5 days of fever and can confirm dengue before antibodies develop.

A screening test for hepatitis B infection. A positive result means the hepatitis B virus is present in your blood — either an active infection or a chronic carrier state.

This test detects antibodies against the Hepatitis C virus (HCV). Hepatitis C is a blood-borne viral infection that primarily affects the liver and can cause chronic liver disease if untreated.

Screening test for Human Immunodeficiency Virus. Modern tests detect both antibodies and antigens (4th generation), catching infection earlier than older tests.

The malaria rapid diagnostic test detects proteins (antigens) produced by malaria parasites in your blood. It can distinguish between Plasmodium falciparum (more dangerous) and Plasmodium vivax (more common in India).

Procalcitonin (PCT) is a blood marker that rises specifically in response to bacterial infections. It helps doctors distinguish bacterial infections from viral infections and guides antibiotic use.

Typhidot IgM is a more specific test for typhoid than the Widal test. It detects IgM antibodies against a specific outer membrane protein of Salmonella typhi.

Urine culture grows bacteria from a urine sample to diagnose urinary tract infections (UTIs). It identifies the exact bacteria causing the infection and which antibiotics will effectively treat it. A clean, mid-stream sample is essential for accurate results.

VDRL is a screening test for syphilis, a sexually transmitted infection caused by the bacterium Treponema pallidum. It detects antibodies that your body makes in response to the infection.

The Widal test detects antibodies against the Salmonella bacteria that causes typhoid fever. It measures O and H agglutinins in your blood. Very commonly ordered in India, though its accuracy is debated.

CPK (creatine phosphokinase) is an enzyme found mainly in muscles, the heart, and the brain. When muscle cells are damaged, CPK leaks into the blood. It's a key marker for muscle injury, heart attacks, and muscle diseases.

Protein produced by prostate gland. Screening tool for prostate cancer. Liquefies semen. Elevated in prostate disorders.

Amylase is an enzyme produced mainly by your pancreas and salivary glands that helps digest starch (carbohydrates). High levels in blood usually indicate pancreatic inflammation.

Lipase is an enzyme made by the pancreas that digests fats. It is the most specific blood test for pancreatitis — more accurate than amylase for diagnosing pancreatic inflammation.

The fecal occult blood test (FOBT) detects hidden (occult) blood in your stool that is invisible to the naked eye. Even tiny amounts of bleeding in the stomach or intestines can be detected. It is an important screening test for colorectal cancer.

A stool routine examination checks the physical and microscopic characteristics of your stool — color, consistency, presence of mucus, blood, parasites, ova (eggs), cysts, pus cells, and red blood cells. It is a basic but important test for diagnosing digestive and parasitic diseases.

AFP is a protein normally produced by the fetal liver during pregnancy. In non-pregnant adults, it's present in very small amounts. It's used to monitor certain liver and germ cell conditions, but elevation does NOT always indicate cancer.

Beta-HCG is the hormone produced during pregnancy — it's what pregnancy tests detect. In non-pregnant individuals, very small amounts may be present. It's also used to monitor certain germ cell tumors, but elevation in non-pregnant women most commonly indicates early pregnancy.

CA 15-3 is a protein that can be shed into the blood by breast cells. It's used to monitor breast cancer treatment, NOT to screen for breast cancer. An elevated level does NOT mean you have cancer.

CA 19-9 is a protein found on the surface of certain cells. It's primarily used to monitor pancreatic cancer treatment, but many non-cancerous conditions can raise it — a high CA 19-9 does NOT mean cancer.

CA-125 is a protein found on the surface of many cells, especially ovarian cells. It's used to monitor ovarian cancer treatment, but elevated levels are common in many benign conditions — a high CA-125 alone does NOT mean cancer.

CEA is a protein involved in cell adhesion. It's mainly used to monitor colorectal cancer treatment response and detect recurrence, but many benign conditions — especially smoking — can elevate it. A high CEA does NOT mean cancer.

PSA is a protein made by the prostate gland. It's used as a screening tool for prostate health, but elevated levels do NOT automatically mean cancer — many benign conditions can raise it too.

A comprehensive analysis of your urine — color, clarity, pH, and chemical dipstick tests for protein, glucose, blood, and more. Often the most overlooked test on a health checkup despite being highly informative.

Essential trace mineral for iron metabolism and connective tissue formation. Iron metabolism, connective tissue formation, energy production, nervous system function, melanin production.

Folate (vitamin B9) is crucial for cell division, DNA synthesis, and preventing neural tube defects in pregnancy. Found in leafy greens, lentils, and fortified foods.

Essential trace mineral with antioxidant properties and thyroid function support. Antioxidant defense, thyroid hormone metabolism, DNA synthesis, immune function, reproduction.

Vitamin A is essential for vision, immune function, and skin health. It exists as retinol in your blood and helps your eyes adjust to darkness.

Vitamin B1 (thiamine) is essential for converting food into energy and for nerve function. It plays a critical role in brain health and carbohydrate metabolism.

Vitamin B12 is essential for nerve function, red blood cell production, and DNA synthesis. It's found almost exclusively in animal products, making deficiency extremely common among vegetarians — a large portion of India's population.

Vitamin B6 is involved in over 100 enzyme reactions, mostly related to protein metabolism. It's crucial for brain development, immune function, and making hemoglobin.

Essential B-vitamin involved in protein metabolism and neurotransmitter synthesis. Critical for amino acid metabolism, neurotransmitter production (serotonin, dopamine), hemoglobin synthesis, and immune function.

Vitamin D is essential for calcium absorption, bone health, immune function, and mood. Your body makes it from sunlight, but despite India's abundant sunshine, deficiency is shockingly common — dark skin, indoor lifestyles, pollution, and cultural clothing practices all reduce production.

Vitamin E is a powerful antioxidant that protects your cells from damage. It also supports immune function, skin health, and helps prevent blood clots.

Essential trace mineral for immune function, wound healing, and DNA synthesis. Critical for immune function, protein synthesis, wound healing, DNA synthesis, cell division, taste and smell.